Access to clean water is a problem faced by many regions of the world. Water is often treated to remove contaminants before it is consumed. Water filters are commonly used for this purpose.
In developing countries, potable water is often unavailable or difficult to obtain.
People who camp may want a water filter that is portable and easy to use because water is heavy and bulky to carry. Victims of disasters may require filtration devices if sources of treated water are not readily available; the devices need to be stored, transported, and distributed. These scenarios highlight the need for a cheap, portable, and easy-to-use filtration device to provide clean water for these types of applications.
A common problem with existing water filters is that it is difficult to generate sufficient pressure to drive or draw water through the filter. Typically, water filters rely on gravity, incorporate pumps, or require a user's lung power to drive water through the filter. However, each of these means of pressurization has drawbacks. In many parts of the world, pumps are prohibitively expensive or present maintenance challenges. Using gravity to generate pressure requires significant vertical distances to build up head pressure, or else the flow rate is inconveniently slow. It is challenging or impossible for many users, such as children and the elderly, to create sufficient pressure to use a filter with just their lung power. For this reason, a water treatment system with an easier means of generating pressure is needed.
An additional problem with water filtration systems is that the filters are easily blocked with debris and must be cleaned. After a period of use, many filters lose efficiency. Particulate matter filtered out of untreated water might have accumulated and clogged the filter. Efficiency may be restored by periodic back-washing, a process of driving water through the filter in the direction countercurrent to the normal filtering mode to dislodge particles accumulated in the filter and flush them away. Typical cleaning processes involve back-washing the filter by generating pressure in this countercurrent direction with a separate pump or bulb system, or disassembling the system and manually cleaning the filter. Cleaning a filter is often a complex operation and these complexities can be difficult for many users.
The foregoing examples of the related art and limitations related thereto are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon a reading of the specifications and a study of the drawings.